Direct blue disazo dyestuff



PIO CACGIA, OF NEW YORK, N. Y.

DIRECT BLUE DISAZO DYES'IUFF.

No Drawing.

The object of my invention is the production of a direct color, which can dye the artificial silk only in unions, (mixed in textiles) while the silk will remain white. The

artificial silk will be dyed light blue shade when in a bath with soap and sodium carbonate, and navy blue in a bath with Glaubers salt (Na SO In carrying out my invention, I boil the H acid (L8-aminonaphthol-3:G-disulfonic acid) with a solution of sodium cyanide and also boil the solution of sodium cyanide with Dahls acid (Q-naphthylamine-5-sulfonic acid), and when boiling I mix the two solutions and then pour into the mixture diazotized benzidine. The smell of hydrocyanic acid disappear and the crystals will be formed with addition of sodium carbonate and sodium chloride. After one night I filter and the dyestufi is dried. The proportion used is 1 mole of H acid to 1 mole Dahls acid to 1 mole of benzidine. The mixture of Na CO and NaOl can be added directly to the mixture of the two acids.

The direct color is very good to washing and the fastness to light increases with the treatment of sodium cyanide.

In preparing this product I prefer to use the ingredients in about the following pro portions: 2 liters of 0.2% sodium cyanide solution; 15 grs. of H acid and 15 grs. of Dahls acid, 2:5; 4 grs. of benzidine sulphate which must be diazotized before use. This color is very soluble in water giving a blue-violet; with H SO a blue-cobalt; with NaOH a red-purple and with H01 a red- Violet.

Application filed September 25, 1925.

I claim 1. A process of making blue disazo dye,

Serial No. 58,608.

ITED STATES PATENT OFFICE.

which comprises reacting diazotized benzidine with 2-naphthylamine-5-sulfonic ac1dand 1.8-am111onaphthol-3:6-disulfonic acid in the presence of a soluble cyanide.

2. A process of making blue disazo dye which consists in treating the diazotized benzidine with the mixture of 2-naphthylamine- 5-sulfonic acid and 1.S-aminonaphthol-3:6-

disulfonic acid in boilin sodium cyanidev solution.

4. A new blue capable of dyeing artificial silk directly resulting from the combination of diazotized benzidine with Q-naphthylamine-5-sulfonic acid and l.8aminonaphthol- 3:6-disulfonic acid in presence of cyanide.

5. The blue disazo d the following formula:

6. Material dyed with the dyestuif of claim 5.

ye having probably NHCN F10 CACCIA. 

